People often ask Bonjour Paris to explain French etiquette—or rather what the French expect people to do and what they definitely do not like. During the 21 years I’ve been a resident of France, customs have relaxed—but not as much as you might think.

The French are more formal in their personal relationships, so it’s understandable—but not always understood—that Americans’ bonhomie can turn into a series of gaffes. These may not be deal-breakers or complete disasters, but little faults can be seen as slights, and anyway who wants to appear unsophisticated? Little things take on importance, so it’s worth your while to know what you’re supposed to do and say.

For example, unless you’re very young, French people greet one another with a Bonjour while shaking hands. A woman who’s in a business situation is addressed as “Madame” whether or not she’s married. After a female is out of school, she’s Madame rather than Mademoiselle. Until you’re instructed to call her (or a male colleague) by their first names, don’t. And don’t use the familiar tu form of verbs until someone uses it to you. The French have a sense of when the time has come: assume you do not.

Thirty years ago, it was rare when a French person would smile at a stranger. Thank goodness life is becoming less rigid. However, the French, when walking down the street, are pros at not making eye contact with people they don’t know. If they bump into friends, expect to see a round of kisses. One on each cheek if you’re in Paris, three pecks if you’re in other parts of France—but Parisians assume they are Belgians. And then there are the teens and college students who will kiss four times in quick succession. It can be confusing.

The French maintain “personal space” in a way most Americans don’t. Go into any Paris café and you’ll rarely see the French striking up conversations with strangers. It’s different if they’re in a tabac (the same one they frequent each morning) for coffee. If the barman knows them, it’s possible they’ll end up speaking to one another because they’ve been introduced. Gone are the days of asking someone for a light for a cigarette because, unless they’re sitting outside, it’s definitely no smoking.

Another annoying trait about the French is they were born with perfect posture. If they slouch, it’s due to a physical impairment, and most people try to cure it by going to a physical therapist, which is covered by French health-care system. You can always differentiate a French person from an American by how straight he or she stands. Some French people swear it’s by how loud Americans speak—but that’s not necessarily the case. Still, keeping your voice down is a good idea. The French by nature aren’t eavesdroppers and really don’t want to hear other’s conversations.

Even though the French are quick to use hand gestures (nothing compared to Italians), they’ll rarely shake or point a finger at others. It’s simply considered rude. Whatever you do, never snap your fingers. It’s a sure recipe for being ignored by taxi drivers (who aren’t supposed to pick up passengers unless they’re at a taxi stand anyway), and if you ever snap your fingers at a waiter, count on being the last person in the restaurant to ever be served.

Americans are quick to make the figure O with their fingers to indicate that everything’s OK. In France, it’s construed in a totally different way and is enough to offend your companion. In essence, you’re saying someone is a big zero and it’s not taken lightly.

These are just a few cultural differences. Please feel free to add more. My French friends consistently ask for advice when they’re heading to the U.S. The difference is, that when they commit a faux-pas, it’s usually considered charming. Their accents go a long way in the manners game and their basic manners, sorry to say, tend to be better than ours.